Because Saint Seiya (movie name) was the first movie of the series, have done a show in live action about him, and normal actors interpreted the Ghost Five.
Yan is the Scutum Saint. Had one of most power full shields between the saints, like the Draco and Libra shields. He, like Algol and Dohko, because of his shield, has a connection with Shiryu, and fight against him. His main attack, is uses his body like a drill, and attacks the enemy destroying his cloth. He breaks Shiryu's shield and cloth, and Shiryu fall injured after defeats Yan.
Christ is the Crux Saint, and is connected with Hyoga (Cygnus is the Northern Crux). He is not acryomancer, but uses a blue thunder in the shape of a cross. He almost kills Hyoga, but Eris kill Christ to try kill Hyoga (or he host a bit of Eiri's love for Hyoga).
His name is the opposite of Seiya, so, evidences that he was created by the fight against Seiya. Maiya is a hunter that never allows a prey scape of his poison arrows (in his epoch, arrows were the main weapon to hunt). His arrow can the victim lose his 5 senses in 1 hour. Seiya is hit by one of his arrows, and is impaireda bit of time later.
Is the legendary minstrel of saints, and Lyre Saint; Shun and Ikki fought against Mime, in tribute of their fight against Orpheu. The lyre of Orpheus with its strings, defeats Shun almost shattering him, but Ikki saves his brother and uses the Phoenix Genma Ken. But it doesn't work in Orpheu, because as a Ghost Saint, already saw the Hell and the Hell is the worst thing he can see. But, with the Phoenix Hoyoku Tensho, Ikki defeats Orpheu.
Jaga was the most powerful saint, ergo, the most powerful ghost saint. He has an attack that kills the enemy with a meteor kick. He is the servant that Eris trusts and because this, Jaga don't lead Eris alone. He defeats Ikki, but Seiya with the Sagittarius cloth, defeats Jaga.